In a known print head, the print head comprises a surface having arranged therein at least one nozzle. Ink is ejected from the print head through said nozzle. When printing, ink may be spilled on the nozzle surface of the print head. Ink present on the nozzle surface close to a nozzle may have a negative influence on the performance of a print head during jetting of the ink. Therefore, it is important to prevent the presence of contaminants, such as ink, on the nozzle surface. Hence, an anti-wetting coating may be applied to the nozzle surface to prevent ink from staying on the nozzle surface. However, it is undesired that the anti-wetting coating is present in the inside of the nozzle, because this may result in jetting problems.
Nozzles surfaces may be prepared in a process comprising one or more etching steps, wherein through holes are formed in a plate. These through holes may serve as nozzles when the plate is incorporated in a print head as a nozzle surface. Because it is preferred to have a nozzle surface provided with an anti-wetting coating on an exterior surface of the nozzle surface, but not in the inside of the nozzle, preferably no anti-wetting coating is applied in the inside of the nozzle when manufacturing a nozzle surface of a print head. However, this is difficult to achieve when using known coatings and production procedures. Known manufacturing procedures for preparing a nozzle surface comprise applying a resist layer to one surface of the substrate forming the nozzle surface. However, if such substrate is already provided with an anti-wetting coating, the etch resist may not adhere to the coated substrate and consequently, etching may take place at unwanted positions. When applying an anti-wetting coating after the etching has taken place, it is difficult to selectively apply the coating to an exterior surface of the nozzle surface without coating the inside of the nozzle.
It is therefore an object of the invention to provide a coating and a production method for applying the coating that mitigate the above problems.